Shrub rose plant named `AC William Booth`

ABSTRACT

A new and distinct variety of shrub rose plant is provided which forms attractive dark red single blossoms that tend to lighten somewhat to pink when fully mature. The new variety exhibits a large arching shrub growth habit with dark green foliage that exhibits glossiness on the upper surface, and good winter hardiness. The blossoms are round when viewed from above with somewhat flattened upper and lower parts when viewed from the side. Good resistance to powdery mildew and blackspot have been observed. The leaflets most commonly number seven per leaf. The new variety propagates well by the use of soft wood stem cuttings, and is well adapted for growing as ornamentation in the landscape.

SUMMARY OF THE INVENTION

The new Rosa hybrida variety of shrub rose plant of the presentinvention was selected during 1987 following artificial pollinationcarried out in 1984 at the Central Experimental Farm, Ottawa, Ontario,Canada. The female parent (i.e., the seed parent) was an unnamed linedesignated `L83` (non-patented in the United States) and the male parent(i.e., the pollen parent) was an unnamed line designated `A72`(non-patented in the United States). Each parent had been previouslystudied in the hope that it would contribute the desired attractivecharacteristics to the product of the cross. The `L83` parent isdescribed at HortScience 23(2):415 to 416 (1988) in an article entitled"Rose Germplasm L83". The `A72` parent was obtained in 1980 by a crossbetween the `Arthur Bell` variety (non-patented in the United States)and the `Applejack` variety (non-patented in the United States).Following observation of the offspring of this cross a single plant ofthe new variety was observed and selected.

The parentage of the new variety can be summarized as follows:

    `L83`×`A72`.

It was found that the new variety of shrub rose plant of the presentinvention possesses the following combination of characteristics:

(a) exhibits an arching growth habit with attractive dark green foliagethat bears glossiness on the upper surface,

(b) forms attractive dark red single blossoms that tend to fade tomedium red when fully mature,

(c) propagates well by the use of softwood cuttings,

(d) exhibits good winter hardiness,

(e) exhibits good resistance to powdery mildew and blackspot, and

(f) is particularly well suited for growing as ornamentation in thelandscape.

The rose plants of the new variety can be grown well on their own rootsout-of-doors without protection at L'Assomption, Quebec, Canada. Theblossoms commonly appear continuously for approximately ten weeksbeginning in late-June. Resistance to powdery mildew and blackspot hasbeen observed to date.

When compared to the `John Cabot` variety (non-patented in the UnitedStates), the new variety of the present invention exhibits singleblossoms while those of the `John Cabot` variety are double, formsgenerally smaller blossoms, and forms generally smaller leaves.

The new variety well meets the needs of the horticultural industry. Itcan be grown to advantage as attractive ornamentation in parks, gardens,public areas, and residential landscapes.

The characteristics of the new variety have been found to be homogenousand stable and have been shown to be strictly transmissible by asexualpropagation by the rooting of softwood stem cuttings conducted atL'Assomption, Quebec, Canada, beginning in 1985.

The new variety has been named the `AC William Booth`. Also, the newvariety is a member of the EXPLORER Series of hardy rose plants.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photographs show, as nearly true as it is reasonablypossible to make the same in color illustrations of this character,typical specimens of mature plants and plant parts of the new variety.The illustrated rose plants of the new variety were two to three yearsof age and were photographed during 1995 while growing on their ownroots at L'Assomption, Quebec, Canada.

FIG. 1 -- illustrates a typical specimen of a blossom of the newvariety. The glossy dark green foliage also is shown.

FIG. 2 -- illustrates a typical flowering plant of the new variety whilegrowing in the landscape. The arching growth habit, dark green glossyfoliage, and single dark red fading to medium red blossoms are apparent.

DETAILED DESCRIPTION

The chart used in the identification of colors is that of The RoyalHorticultural Society (R.H.S. Colour Chart). Common color terms are tobe accorded their ordinary dictionary significance. The description isbased on the observation of mature plants of the new variety while beinggrown outdoors at L'Assomption, Quebec, Canada.

Class: Shrub.

Plant:

Height.--A mature plant commonly assumes a height of up to approximately1 m. and a width of approximately 2 m. at the end of the growing season.

Habit.--Arching.

Thorns: Quantity: Medium. Quantity and size: Medium number of longthorns (greater than 5 mm. in length) and the sparse presence of shortthorns. Color: Green Group 139C with tones of Greyed-Purple Group 185B.Configuration: Deep concave.

Leaves: Compound and pinnate.

Leaflets.--Number: 3, 5, and 7 (most common). Shape: Elliptic (asillustrated in FIG. 2) with a rounded base. Margins: Serrate. Size:Commonly approximately 75 to 110 mm. (90 mm. mean) in length andapproximately 55 to 100 mm. (72 mm. mean) in width on average. Texture:Leathery. General appearance: Dark green with strong glossiness on theupper surface.

Color.--Adult foliage: Dark green, Yellow-Green Group 147A on uppersurface and Yellow-Green Group 148A to 147C on under surface dependingon the age. Young foliage: Green Group 137B with Greyed-Purple Group184A on the upper surface and Green Group 137D with Greyed-Purple Group184B on the under surface. Young shoots: Bear very strong anthocyanincoloration.

Petiole.--Greyed-Purple Group 184A on upper surface and Green Group 138Bon under surface.

Stipule.--Green Group 138B with tones of Greyed-Purple Group 183C.

Inflorescence:

Number of flowers.--Commonly approximately 4 to 14 per shoot inclusters.

Peduncle.--Commonly bears many thorns. Green Group 138A and 138B withRed-Purple Group 59B.

Sepals.--With medium extensions, and commonly approximately 12 to 15 mm.(14 mm. mean) in length. Green Group 138C and 138D on the upper surfaceand Green Group 138A and 138B with Red-Purple Group 59B on the undersurface.

Buds.--Shape: Pointed in longitudinal section. Color upon opening:Red-Purple Group 57A on the upper surface and Red Group 61C on the undersurface.

Flower.--Shape: Single, round when viewed from above with flat upper andlower parts. Diameter: Commonly approximately 40 to 60 mm. (50 mm.mean). Color (when blooming): The overall blossom coloration initiallyis Red-Purple Group 57A, and when open the upper petal surface isRed-Purple Group 57A and under petal surface is Red-Purple Group 57C.The coloration of the blossoms commonly fades to pink, near Red-PurpleGroup 57C, when the blossoms are fully mature. The petals have asmall-sized yellow spot at the base that is Yellow Group 10A on bothsurfaces.

Petal configuration.--Possess some reflexing and undulation.

Fragrance.--Weak.

Petal number.--5.

Filaments.--Yellow in coloration.

Pollen.--Beige-yellow in coloration.

Style.--Short, and yellow-green in coloration with weak pubescence onthe upper one half.

Stigma.--Commonly disposed below the anthers.

Petal drop.--Petals comonly detach cleanly and exhibit a good petaldrop.

Receptacle.--Small and pear-shaped with prickles.

Lasting quality.--Approximately 5 to 7 days on the plant depending uponthe environmental conditions.

Duration.--Blossoms commonly are formed beginning in mid-season (e.g.,approximately June 24th) continuously over a period of 10 weeks or morewhen grown in the landscape.

Hips.--Round orange-red shiny hips commonly are formed on an abundantbasis.

Development:

Blossoming.--Continuous.

Hardiness.--Has survived winter temperatures of -28° C. to -30° C.

Resistance to diseases.--Is resistant to powdery mildew [Sphaerotheapannosa (Wallr. ex Fr.) Lev.] and blackspot (Diplocarpon rosae Wolf.)during observations to date.

Preferred mode of propagation.--The use of softwood cuttings to produceself-rooted plants is recommended. For instance, softwood cuttings takenat the bud stage can be dipped in rooting powder (e.g., Stimroot No. 2,0.4 percent indolebutyric acid of Plant Products, Bramalea, Ontario,Canada) and placed under mist for 3 to 4 weeks at 20 to 25° C. ambienttemperature.

I claim:
 1. A new and distinct variety of shrub rose plant characterizedby the following combination of characteristics:(a) exhibits an archinggrowth habit with attractive dark green foliage that bears glossiness onthe upper surface, (b) forms attractive dark red single blossoms thattend to fade to pink when fully mature, (c) propagates well by the useof softwood cuttings, (d) exhibits good winter hardiness, (e) exhibitsgood resistance to powdery mildew and blackspot, and (f) is particularlywell suited for growing as ornamentation in the landscape;